YL has done part of the experiment, has drafted the manuscript and revised it. JG has supervised the experiment, have been involved in revising it critically for important intellectual content. DJ, YG did part of the experiment; MY has supervised the experiment. All authors read and approved the final manuscript. Authors’ information Yingying Lu, Ph.D., Associate professor, Department of Medicine, Beijing Friendship Hospital affiliated to Capital Medical University, Beijing, China 100050 Junchao Gu, Ph.D., Professor, Department of Medicine, Beijing Friendship Hospital affiliated to Capital Medical University, Beijing, China 100050″“Background Acetaldehyde (ethanal, CH3CHO) is a potent volatile flavouring

compound found in many beverages and foods [1–3]. In alcoholic beverages, acetaldehyde may be formed by yeast, acetic acid bacteria, and by coupled auto-oxidation selleck compound of ethanol and phenolic compounds [3]. In a recent study, a large collective of different alcoholic beverages (n > 1500) was PF-562271 in vivo evaluated. Beer (9 ± 7 mg/l, range 0-63 mg/l) contained significantly lower amounts of acetaldehyde than wine (34 ± 34 mg/l, range 0-211 mg/l), or spirits (66 ± 101 mg/l, range 0-1159 mg/l) [4]. According to the International Agency for Research on Cancer (IARC), acetaldehyde associated with alcohol consumption is regarded as ‘carcinogenic to humans’ (IARC Group 1) [5]. Evidence points to the oesophagus, head and neck as principal sites of carcinogenicity of metabolically or microbiologically formed acetaldehyde. A causal link has been found between alcohol consumption and the occurrence of malignant tumours of the oral cavity, pharynx, larynx, oesophagus, as well as of liver, colorectum, and female breast, so that ethanol in alcoholic beverages is also considered to be ‘carcinogenic to humans’ (IARC Group 1) [6, 7].